package com.zhongkai.tools;

import java.util.*;
import java.security.SecureRandom;
import java.security.NoSuchAlgorithmException;
import java.security.NoSuchProviderException;

/**
 * <p>Title:商务e</p>
 * <p>Description: </p>
 * <p>Copyright: Copyright (c) 2005</p>
 * <p>Company: </p>
 * @author 余伟明
 * funtion 随机生成指定长度的验证码字符串
 * @version 1.0
 */


public class RandomStrg
{

  private String randomstr;
  private boolean allchars = false;
//欠缺是8位字符串
  private Integer length = new Integer(8);
  private HashMap hmap;
  private ArrayList lower = null;
  private ArrayList upper = null;
  private char[] single = null;
  private int singlecount = 0;
  private boolean singles = false;
  private String algorithm = null;
  private String provider = null;
  private boolean secure = false;
  private Random random = null;
  private SecureRandom secrandom = null;

  private final float getFloat()
  {
    if (random == null)
      return secrandom.nextFloat();
    else
      return random.nextFloat();
  }

  /**
   * generate the Random object that will be used for this random number
   * generator
   *
   */
  public final void generateRandomObject() throws Exception
  {

// check to see if the object is a SecureRandom object
    if (secure)
    {
      try
      {
// get an instance of a SecureRandom object
        if (provider != null)
// search for algorithm in package provider
          random = SecureRandom.getInstance(algorithm, provider);
        else
          random = SecureRandom.getInstance(algorithm);
      }
      catch (NoSuchAlgorithmException ne)
      {
        throw new Exception(ne.getMessage());
      }
      catch (NoSuchProviderException pe)
      {
        throw new Exception(pe.getMessage());
      }
    }
    else
      random = new Random();
  }

  /**
   * generate the random string
   *
   */
  private final void generaterandom()
  {

    if (allchars)
      for (int i = 0; i < length.intValue(); i++)
        randomstr = randomstr + new Character((char) (34 +
            ((int) (getFloat() * 93)))).toString();
    else if (singles)
    {
// check if there are single chars to be included

      if (upper.size() == 3)
      {
// check for the number of ranges max 3 uppercase lowercase digits

// build the random string
        for (int i = 0; i < length.intValue(); i++)
        {
// you have four groups to choose a random number from, to make
// the choice a little more random select a number out of 100

// get a random number even or odd
          if (((int) (getFloat() * 100)) % 2 == 0)
          {

// the number was even get another number even or odd
            if (((int) (getFloat() * 100)) % 2 == 0)
// choose a random char from the single char group
              randomstr = randomstr + randomSingle().toString();
            else
// get a random char from the first range
              randomstr = randomstr + randomChar((Character) lower.get(2),
                                                 (Character) upper.get(2)).
                  toString();
          }
          else
          {
// the number was odd

            if (((int) (getFloat() * 100)) % 2 == 0)
// choose a random char from the second range
              randomstr = randomstr + randomChar((Character) lower.get(1),
                                                 (Character) upper.get(1)).
                  toString();
            else
// choose a random char from the third range
              randomstr = randomstr + randomChar((Character) lower.get(0),
                                                 (Character) upper.get(0)).
                  toString();
          }
        }
      }
      else if (upper.size() == 2)
      {
// single chars are to be included choose a random char from
// two different ranges

// build the random char from single chars and two ranges
        for (int i = 0; i < length.intValue(); i++)
        {
// select the single chars or a range to get each random char
// from

          if (((int) (getFloat() * 100)) % 2 == 0)
          {

// get random char from the single chars
            randomstr = randomstr + randomSingle().toString();
          }
          else if (((int) (getFloat() * 100)) % 2 == 0)
          {

// get the random char from the first range
            randomstr = randomstr + randomChar((Character) lower.get(1),
                                               (Character) upper.get(1)).
                toString();
          }
          else
          {

// get the random char from the second range
            randomstr = randomstr + randomChar((Character) lower.get(0),
                                               (Character) upper.get(0)).
                toString();
          }
        }
      }
      else if (upper.size() == 1)
      {

// build the random string from single chars and one range
        for (int i = 0; i < length.intValue(); i++)
        {
          if (((int) getFloat() * 100) % 2 == 0)
// get a random single char
            randomstr = randomstr + randomSingle().toString();
          else
// get a random char from the range
            randomstr = randomstr + randomChar((Character) lower.get(0),
                                               (Character) upper.get(0)).
                toString();
        }
      }
      else
      {
// build the rand string from single chars
        for (int i = 0; i < length.intValue(); i++)
          randomstr = randomstr + randomSingle().toString();
      }
    }
    else
    {

// no single chars are to be included in the random string
      if (upper.size() == 3)
      {

// build random strng from three ranges
        for (int i = 0; i < length.intValue(); i++)
        {

          if (((int) (getFloat() * 100)) % 2 == 0)
          {

// get random char from first range
            randomstr = randomstr + randomChar((Character) lower.get(2),
                                               (Character) upper.get(2)).
                toString();
          }
          else if (((int) (getFloat() * 100)) % 2 == 0)
          {

// get random char form second range
            randomstr = randomstr + randomChar((Character) lower.get(1),
                                               (Character) upper.get(1)).
                toString();
          }
          else
          {

// get random char from third range
            randomstr = randomstr + randomChar((Character) lower.get(0),
                                               (Character) upper.get(0)).
                toString();
          }
        }
      }
      else if (upper.size() == 2)
      {

// build random string from two ranges
        for (int i = 0; i < length.intValue(); i++)
        {
          if (((int) (getFloat() * 100)) % 2 == 0)
// get random char from first range
            randomstr = randomstr + randomChar((Character) lower.get(1),
                                               (Character) upper.get(1)).
                toString();
          else
// get random char from second range
            randomstr = randomstr + randomChar((Character) lower.get(0),
                                               (Character) upper.get(0)).
                toString();
        }
      }
      else

// build random string
        for (int i = 0; i < length.intValue(); i++)
// get random char from only range
          randomstr = randomstr + randomChar((Character) lower.get(0),
                                             (Character) upper.get(0)).toString();
    }
  }

  /**
   * generate a random char from the single char list
   *
   * @returns - a randomly selscted character from the single char list
   *
   */
  private final Character randomSingle()
  {

    return (new Character(single[(int) ((getFloat() * singlecount) - 1)]));
  }

  /**
   * generate a random character
   *
   * @param lower lower bound from which to get a random char
   * @param upper upper bound from which to get a random char
   *
   * @returns - a randomly generated character
   *
   */
  private final Character randomChar(Character lower, Character upper)
  {
    int tempval;
    char low = lower.charValue();
    char up = upper.charValue();

// get a random number in the range lowlow - lowup
    tempval = (int) (low + (getFloat() * ((up - low))));

// return the random char
    return (new Character((char) tempval));
  }

  /**
   * get the randomly created string for use with the
   * &lt;jsp:getProperty name=<i>"id"</i> property="randomstr"/&gt;
   *
   * @return - randomly created string
   *
   */
  public final String getRandom()
  {

    randomstr = new String();

    generaterandom(); // generate the first random string

    if (hmap != null)
    {

      while (hmap.containsKey(randomstr))
      {
// random string has already been created generate a different one
        generaterandom();
      }

      hmap.put(randomstr, null); // add the new random string
    }

    return randomstr;
  }

  /**
   * set the ranges from which to choose the characters for the random string
   *
   * @param low set of lower ranges
   * @param up set of upper ranges
   *
   */
  public final void setRanges(ArrayList low, ArrayList up)
  {
    lower = low;
    upper = up;
  }

  /**
   * set the hashmap that is used to check the uniqueness of random strings
   *
   * @param map hashmap whose keys are used to insure uniqueness of random strgs
   *
   */
  public final void setHmap(HashMap map)
  {
    hmap = map;
  }

  /**
   * set the length of the random string
   *
   * @param value length of the random string
   *
   */
  public final void setLength(String value)
  {
    length = new Integer(value);

  }

  /**
   * set the algorithm name
   *
   * @param value name of the algorithm to use for a SecureRandom object
   *
   */
  public final void setAlgorithm(String value)
  {
    algorithm = value;
    secure = true; // a SecureRandom object is to be used
  }

  /**
   * set the provider name
   *
   * @param value name of the package to check for the algorithm
   *
   */
  public final void setProvider(String value)
  {
    provider = value;
  }

  /**
   * set the allchars flag
   *
   * @param value boolean value of the allchars flag
   *
   */
  public final void setAllchars(boolean value)
  {
    allchars = value;
  }

  /**
   * set the array of single chars to choose from for this random string and the
   * number of chars in the array
   *
   * @param chars the array of single chars
   * @param value the number of single chars
   *
   */
  public final void setSingle(char[] chars, int value)
  {
    single = chars; // set the array of chars
    singlecount = value; // set the number of chars in array single
    singles = true; // set flag that single chars are in use
  }

  public final void setCharset(String value)
  {
// values tells the method whether or not to check for single chars
    boolean more = true;

// create the arraylists to hold the upper and lower bounds for the char
// ranges
    lower = new ArrayList(3);
    upper = new ArrayList(3);

// user has chosen to use all possible characters in the random string
    if (value.compareTo("all") == 0)
    {
      allchars = true; // set allchars flag
// all chars are to be used so there are no single chars to sort
// through
      more = false;
    }
    else if ((value.charAt(1) == '-') && (value.charAt(0) != '\\'))
    {
// run through the ranges at most 3
      while (more && (value.charAt(1) == '-'))
      {

// check to make sure that the dash is not the single char
        if (value.charAt(0) == '\\')
          break;
        else
        {
// add upper and lower ranges to there list
          lower.add(new Character(value.charAt(0)));
          upper.add(new Character(value.charAt(2)));
        }

// check to see if there is more to the charset
        if (value.length() <= 3)
          more = false;
        else
// create a new string so that the next range if there is one
// starts it
          value = value.substring(3);
      }
    }

// if more = false there are no single chars in the charset
    if (more)
    {

      single = new char[30]; // create single

// create a set of tokens from the string of single chars
      StringTokenizer tokens = new StringTokenizer(value);

      while (tokens.hasMoreTokens())
      {
// get the next token from the string
        String token = tokens.nextToken();

        if (token.length() > 1)
// char is a - add it to the list
          single[singlecount++] = '-';

// add the current char to the list
        single[singlecount++] = token.charAt(0);
      }
    }
    if ((lower == null) && (single == null))
      setCharset("a-zA-Z0-9");
  }
}
